EP0384845B1 - Apparatus with winding and unwinding device for eliminating torsion in connecting cable at the rotatable coupling - Google Patents

Abstract

The invention relates to a winding and unwinding device for eliminating the torsion of a connecting cable (16) in a rotatable coupling between a fixed element and a moveable element, to which elements are respectively fixed the two ends of the connecting cable, of the type comprising a fixed reel (12) and a moveable reel (14) with the same axis (A) which are capable of being securely fastened, respectively, to the fixed and moveable elements of the coupling, and an arm (22) capable of rotating about the said axis and carrying at its end a satellite pulley (20) which, when it rotates at a speed less than the speed of rotation of the moveable reel, transfers the connecting cable of the moveable reel to the fixed reel or vice versa, and means for rotatably driving the arm, comprising at least one sliding coupling unit (26, 28; 26), the primary of which is connected to the moveable reel via a first free-wheel mechanism (30) and to the fixed reel via a second free-wheel mechanism (32), and the secondary of which is integral with the arm. <??>It is characterised in that: - the fixed reel (12) and the moveable reel (14) are narrow reels disposed close to each other and - the satellite pulley (20) rotates about an axis (A') which is slightly inclined in relation to the common axis (A) of the fixed and moveable reels. <IMAGE>

Description

The present invention relates to a winder-unwinder device for canceling the twisting of a link in a rotary link between a fixed element and a mobile element, to which the two ends of the link are fixed respectively.

Already known in the prior art, in particular from patent FR-A-2 188 593, a winder-unwinder device comprising a fixed spool and a moving spool of the same axis, designed to be made respectively integral with the fixed element and the movable element of the rotary link, and an arm capable of rotating around said axis and carrying at its free end a satellite pulley which, when it rotates at a speed lower than the speed of rotation of the voice coil, transfers the link from the voice coil to the fixed voice or vice versa, and means for driving the rotating arm comprising at least one sliding coupling, the primary of which is connected to the voice coil via a first freewheel mechanism and the fixed coil via a second freewheel mechanism, the secondary of which is secured to the arm.

A major drawback of this known device is that the axis of the satellite pulley is perpendicular to the axis of the coils. As a result, when used with, for example, flat fiber optic cables or the like, substantial twists are applied to the cable, particularly between the coils and the satellite pulley, due to the marked change in direction of said cable.

Furthermore, in this known device, the sliding coupling (s) consist of friction clutches. This type of clutch is disadvantageous in that it is not able to transmit to the arm a constant drive or braking torque. In particular, it occurs during startup or shutdown, given the transition from friction from static to dynamic mode or vice versa, jerks which can prove to be entirely harmful for cables such as optical fibers.

The present invention aims to overcome these drawbacks of the prior art and to propose a winder-unwinder device in which the transfer between the fixed reel and the moving reel, and vice versa, can be carried out extremely regularly, with a tension in the uniform link and printed twists to the link that are minimized.

More specifically, an object of the invention is to provide a device which makes it possible to process links of quite diverse types, and in particular flat cables with optical fibers or the like, without causing significant disturbances in these.

• la bobine fixe et la bobine mobile sont des bobines étroites, disposées à proximité l'une de l'autre, et
• la poulie satellite tourne autour d'un axe faiblement incliné par rapport à l'axe commun des bobines fixe et mobile.

To this end, the present invention relates to a winder-unwinder device of the type indicated in the introduction, characterized in that:

• the fixed coil and the voice coil are narrow coils, arranged close to each other, and
• the satellite pulley rotates around an axis slightly inclined relative to the common axis of the fixed and mobile coils.

In the above definition and in the description which follows, the term "narrow coils" means coils whose number of side-by-side windings is substantially less than the number of windings in superposition. Ultimately, it may be single-coil coils whose internal width is equal to or slightly greater than the width of the link.

• le ou chaque accouplement glissant consiste en un coupleur magnétique.
• il comprend deux accouplements glissants dont les primaires sont respectivement reliés aux deux mécanismes à roue libre et dont les secondaires sont tous deux solidaires du bras.
• les moyens d'entraînement comprennent en outre un arbre d'entraînement solidaire de la bobine mobile, dont une extrémité est apte à être reliée à l'élément mobile de la liaison tournante et dont l'extrémité opposée est reliée au premier mécanisme à roue libre.
• le second mécanisme à roue libre est relié à la bobine fixe par l'intermédiaire d'une pièce fixe située dans le prolongement dudit arbre d'entraînement, cette pièce étant fixée sur un bâti du dispositif sur lequel est également fixée la bobine fixe.
• le bras est solidaire d'un arbre auxiliaire monté rotatif sur les extrémités en vis-à-vis de l'arbre d'entraînement et de la pièce fixe.
• les primaires des deux accouplements glissants sont fixés sur deux flasques montés rotatifs sur ledit arbre auxiliaire.
• il comprend un accouplement glissant unique dont le primaire est fixé sur un flasque relié aux deux mécanismes à roue libre et monté rotatif sur un arbre d'entraînement solidaire de la bobine mobile et apte à être relié à l'élément mobile de la liaison tournante, et le bras est également monté rotatif sur ledit arbre d'entraînement.
• le bras présente la forme générale d'un "L" dont une partie s'étend à l'extérieur desdites bobines et essentiellement perpendiculairement à leur axe et dont l'autre partie est essentiellement parallèle audit axe et porte à son extrémité libre la poulie satellite.

Preferred aspects of the device according to the invention are the following:

• the or each sliding coupling consists of a magnetic coupler.
• it includes two sliding couplings, the primary of which are respectively connected to the two freewheel mechanisms and the secondary of which are both secured to the arm.
• the drive means further comprise a drive shaft secured to the voice coil, one end of which is adapted to be connected to the mobile element of the rotary link and the opposite end of which is connected to the first freewheel mechanism .
• the second freewheel mechanism is connected to the fixed coil via a fixed part located in the extension of said drive shaft, this part being fixed on a frame of the device on which the fixed coil is also fixed.
• the arm is secured to an auxiliary shaft rotatably mounted on the opposite ends of the drive shaft and the fixed part.
• the primaries of the two sliding couplings are fixed on two flanges rotatably mounted on said auxiliary shaft.
• it includes a single sliding coupling, the primary of which is fixed to a flange connected to the two freewheel mechanisms and rotatably mounted on a drive shaft secured to the voice coil and capable of being connected to the mobile element of the rotary link, and the arm is also rotatably mounted on said drive shaft.
• the arm has the general shape of an "L", a part of which extends outside said coils and essentially perpendicular to their axis and the other part of which is essentially parallel to said axis and carries at its free end the satellite pulley .

• les figures 1 et 2 sont des vues en élévation schématiques et partiellement en coupe de dispositifs selon deux formes de réalisation de l'invention, la vue de la figure 2 étant seulement partielle, et
• la figure 3 est une vue de dessus, schématique et partielle, du dispositif de la figure 1.

Other aspects, aims and advantages of the present invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of example limiting and made with reference to the accompanying drawings, in which:

• FIGS. 1 and 2 are schematic elevational views and partially in section of devices according to two embodiments of the invention, the view of FIG. 2 being only partial, and
• FIG. 3 is a top view, schematic and partial, of the device of FIG. 1.

It will first be indicated that, from one figure to another, identical or similar elements or parts are designated by the same reference numbers.

The device shown in Figure 1 is intended to be incorporated in a rotary connection between a movable member and a fixed member (not shown), to which the two ends of a link 16 are respectively fixed, in order to cancel the twisting of said link when the elements rotate relative to each other. It comprises, in a fixed frame 10 integral with the fixed element of the connection, two accumulating coils 12 and 14 between which the link 16, such as a cable, pipe or other, must be transferred when a relative rotation exists between the two coils. The coil 12 is fixed, for example being rigidly mounted on the frame by means of fastening parts 18, while the coil 14 is movable in rotation, being, as will be seen below, secured to the movable element of the rotary link, this movable element being able to be moved by its own drive means. It can for example be a main reel reel, on which the link is wound or from which it is unwound.

In known manner, it is this transfer movement which makes possible a relative rotation of the two ends E1 and E2 of the link, secured respectively to the fixed coil and the voice coil, without generally generating torsion in the latter, thanks to the inversion of direction of winding of the link from one accumulator coil to another.

Conventionally also, this transfer takes place via a so-called satellite return pulley 20 which is mounted idly at the end of an arm 22. This arm 22 can rotate around the axis A common to the coils.

où Rm est le rayon instantané d'enroulement du lien sur la bobine mobile 14, et Rf est le rayon instantané d'enroulement du lien sur la bobine fixe 12.In such a device, assuming that no slack appears in the link, and assuming that the two coils 12 and 14 are geometrically identical, the speed of rotation Vb of the arm 22 is linked to the speed of rotation Vm of the voice coil 14 by the following relation: $$\text{Vb = (Rm / Rf + Rm) .Vm}$$

where Rm is the instantaneous radius of winding of the link on the voice coil 14, and Rf is the instantaneous radius of winding of the link on the fixed coil 12.

Rm and Rf varying during the winding and unwinding, we already note that it is necessary to establish a relationship which evolves over time between the speed of rotation of the voice coil and the speed of arm rotation.

où Ri est le rayon d'enroulement minimal des bobines 12 et 14 (bobines vides) et Re est le rayon d'enroulement maximal des bobines 12 et 14 (bobines pleines).Furthermore, the relationship between the torque Cb applied to the arm 22 to carry out the aforementioned transfer and the tension T in the link is expressed as follows: $$\text{Cb = T. (Rf + √ (Re² + Ri²-Rf²))}$$

where Ri is the minimum winding radius of the coils 12 and 14 (empty coils) and Re is the maximum winding radius of the coils 12 and 14 (full coils).

To obtain a tension T in the link as constant as possible, it is first necessary to ensure that the driving torque Cb applied to the arm is as constant as possible.

We will now describe below the means used in accordance with the invention to fulfill the above conditions, and therefore ensure the transfer of the link under optimal conditions.

The arm 22 carrying the satellite pulley 20 is mounted idly relative to a drive shaft 24 and is connected to this shaft and to the fixed frame 10 by means of two magnetic couplers 26, 28 and two freewheel mechanisms, schematically represented and designated by the references 30 and 32, as will be seen in detail below. The magnetic couplers used have the property of transmitting between the inductor and the armature an essentially constant torque, independently of any slip which may appear between them.

In addition, in order to limit the constraints in the link 16 to a minimum, in particular when the latter is constituted by a flat fiber optic cable, the two accumulator coils 12 and 14 are placed immediately adjacent to one another. other and the axis A ′ of the satellite pulley 20 is only slightly inclined relative to the axis A, as shown in particular in Figure 3. As a corollary, the arm 22 planet carrier has the shape of a "L" to bring the pulley 20 to the right of the border between the two coils passing outside of them.

The drive shaft 24 is designed to be made integral, at its end 24b, with the movable element of the rotary link, for example with a main coil which is itself driven by a drive motor ( these elements not being illustrated). The voice coil 14 is integral with the shaft 24.

The first free wheel 30 provides a positive drive link between the shaft 14 and a primary or armature 26a of the first magnetic coupler 26 in the direction of unwinding of the link 16 from the voice coil 14. The second free wheel 32 is suitable for immobilizing the primary or armature 28a of the second magnetic coupler 28, acting between said armature and a part 34 which is fixed rigidly on the frame 10 of the reel, in the direction of the winding of the link 16 on the voice coil 14. Furthermore, the respective secondary or inductors 26b, 28b of the two couplers 26, 28 are both rigidly fixed on the arm 22.

The device according to this embodiment also has the following particularities. The shaft 22 extends substantially symmetrically on either side of the axis A and carries at its end opposite to the pulley 20 a counterweight 21.

In addition, the arm 22 is rigidly mounted on an auxiliary shaft 36 which is mounted idly by means of bearings 38 in the opposite ends of the drive shaft 24 and the fixed part 34. The armatures 26a, 28a are carried respectively by flanges 26c, 28c which are mounted idly on the shaft 36 by means of bearings, referenced 40, 42.

Finally the fixed end E1 of the link opens into the frame 10 from the bottom of the fixed coil 12, and can continue its path as desired towards any device secured to the frame, while the rotating end E2 of the link opens to the inside the shaft 24, and can continue its path towards any rotating device integral with said shaft.

The operation of the device according to the invention is as follows. In the direction of unwinding of the link 16 from the voice coil, the shaft 24 drives the armature 26a of the coupler 26 via the first free wheel 30. The electromagnetic link between the inductor 26b and the armature 26a transmits then at arm 22 a torque equal to the nominal torque of the coupler, tending to rotate said arm in the same direction as the shaft 24 and the voice coil 14, and at a speed which can vary thanks to a slip in the coupler.

This constant torque has the effect of maintaining in the part of the link located between the two coils accumulators 12 and 14 an essentially constant voltage, the value of which varies only slightly as a function of the development over time of the parameters Rf and Rm as indicated above. The arm 22 and the pulley 20 are thus rotated to ensure the winding of the link 16 on the fixed spool 12 and its unwinding from the voice coil 14.

It may be noted that during this movement, the inductor 28b of the coupler 28 and the associated armature 28a can freely accompany the arm 22 in its rotation, without imparting torque to it, since the armature 28a is free to rotate relative to the part 34 thanks to the freewheel 32, which can only carry out a positive drive in the opposite direction.

In the direction of winding of the link 16 on the voice coil 14, said link drives the arm 22 by acting on the return pulley 20, and simultaneously the arm 22 undergoes a constant braking torque. More specifically, the freewheel 32, urged in the direction of its positive drive, prevents the flange 28c from rotating relative to the fixed part 34 and to the frame. The armature 28a being stationary, it exerts on the arm 22 by magnetic cooperation with the inductor 28b, regardless of the speed of said arm, braking at constant torque. A constant tension is therefore here again maintained in the link.

It can be noted that, in this case, the armature 26a and the inductor 26b of the first coupler 26 are free to rotate in the same direction as the arm 22, and without applying undesirable torque to it, since the wheel mechanism free 30 is then requested in the opposite direction to the positive drive direction.

The advantages of the device according to the present invention are recalled below.

First of all, thanks to the special arrangement of the coils and the satellite pulley, we understand that only a minimal twist is generated in the link 16. In this respect, the angle α between the axis A ′ of the satellite and the axis A of the coils is chosen on a case-by-case basis as a function of the geometry of the various elements. In practice, it can vary, depending on the case, between approximately 0 and 45 ° (approximately 15 ° in FIG. 3).

However, it is desirable for certain types of cables to keep the angle α as small as possible. In this case, if one is led for some reason to use coils wider or more axially spaced, one can, to avoid increasing α accordingly, increase the diameter of the satellite pulley.

In addition, thanks to the use of magnetic couplers, the drive torque of the arm is constant and can be determined precisely by adjusting the couplers 26 and 28. Furthermore, it is possible, if desired, to use different torques in one way and the other. The traction in the link 16 is therefore permanently perfectly controlled, by following the relation (2) mentioned above with only small variations due to the variations of Rf and Rm.

In this regard, it could be demonstrated that, if the ratio between Re and Ri is for example equal to three, the traction applied to the link does not undergo relative variations greater than 12%. These variations fall to only 5% when the aforementioned ratio is equal to two.

Furthermore, whatever the values of the instantaneous winding radii Rf and Rm, the arm 22 and the pulley 20 are always driven at the appropriate speed. In fact, the sliding couplers 26 and 28, in one direction as in the other, allow the arm 22 to adopt any angular speed between 0 and the angular speed Vm of the voice coil 14.

There is shown in the partial elevational view of Figure 2 a second embodiment of the invention. In this figure and the next, elements or parts identical or similar to those in FIG. 1 are designated by the same reference numbers.

In this embodiment, the drive shaft 24 is extended (to the right in the figure) by a part 24a which replaces the auxiliary shaft 36 to support the arm 22 in rotation by means of bearings 50. In addition, this variant comprises only one coupler 26 whose inductor 26b is fixed to the arm 22 and whose armature 26a is fixed to a flange 26c. The flange 26c is mounted on the extension 24a of the drive shaft by means of a first freewheel mechanism 30 and on the fixed part 34 by means of a second freewheel mechanism 32. These two mechanisms are mounted in the same direction as in FIG. 1. Furthermore, the coils 12 and 14 and the satellite 20 are arranged mutually in the same manner as in the case of FIG. 1.

The operation of the device according to this alternative embodiment is completely similar to that of the device of FIG. 1, except that the single coupler 26 plays the role of the two couplers 26, 28 of FIG. 1.

Although the present invention has been described in connection with a main coil for the winding and unwinding of the link, it can also be used for the rotary connection over a finite number of turns, for example between a crane mast and its turret, and more generally in any application in which two elements that can rotate relative to each other must be connected by a link such as a cable, pipe or other, the ends of which are respectively fixed on these elements, without calling to a collector and without inducing torsion in said link. In the aforementioned case of a crane, the frame 10 of the winding device can be fixedly mounted on the mast of the crane, while its turret is fixedly mounted on the coupling part 24b of the drive shaft 24.

Furthermore, although the invention has been described in connection with single-coil accumulator coils, it is understood that it applies to coils comprising several turns. However, in the case of links to which we must impart as little twist as possible when transferring them from one reel to the other (for example flat fiber optic cables), the number of turns will be reduced as much as possible. The angle α mentioned above will also be adjusted as a function of the width of the coils.

In addition, those skilled in the art will be able to implement the concepts of the invention as expressed above in order to produce a device comprising several pairs of accumulator coils, with each pair being associated with its own satellite pulley.

Finally, the notions of fixity and mobility used throughout this description are to be considered in a relative sense. For example, the drive shaft 24 can be fixed, while it is the frame 10 which is rotated and secured to the movable member of the rotary link. It is also conceivable that the two elements of the rotary link rotate with a differential rotation.

Claims (9)

1. Paying out /winding in device for eliminating torsion in a line (16) in a rotary connection between a fixed member and a mobile member to which respective ends of said line are fixed, of the type comprising a fixed spool (12) and, a mobile spool (14) having the same axis (A), arranged to be made fixed relative to the fixed member and the mobile member of the rotary connection , respectively, and an arm (22) rotatable about said axis and carrying at its free end a satellite pulley (20) which, when rotating more slowly than the mobile spool, tranfers the line from the mobile spool to the fixed spool or vice-versa, and drive means for rotating the arm comprising at least one sliding coupling (26, 28, 26) the primary member of which is coupled to the mobile spool via a first free wheel mechanism (30) and to the fixed spool via a second freewheel mechanism (32), and the secondary member of which is fastened to the fixed spool, characterized in that:

   - the fixed spool (12) and the mobile spool (14) have a small width and are arranged near each other, and

   - the satellite pulley (20) rotates about an axis (A′) having a small inclination relative to the common axis (A) of the fixed and mobile spools.
2. Device according to claim 1 characterized in that said at least on sliding coupling (26, 28; 26) is a magnetic coupling.
3. Device according to claim 1 or 2, characterized in that it comprises two sliding couplings (26, 28) each having its primary member coupled to a respective freewheel mechanism (30, 32) and its secondary member fastened to said arm (22).
4. Device according to claim 3, characterized in that said drive means further comprise a drive shaft (24) fastened to said mobile spool (14), one end (24b) of which is adapted to be coupled to the mobile member of the rotary connection, its opposite end being coupled to the first freewheel mechanism (30).
5. Device according to claim 4, characterized in that said second freewheel mechanism (32) is coupled to the fixed spool (12) by a fixed member (34) aligned with said drive shaft (24) , said member being fixed to a frame (10) of the device to which said fixed spool (12) is also fixed.
6. Device according to claim 5, characterized in that said arm (22) is fastened to an auxiliary shaft (36) mounted to rotate on mutually facing ends of said drive shaft (24) and said fixed member (34).
7. Device according to claim 6, characterized in that said primary members of said two sliding couplings (26, 28) are fixed to two flanges (26c, 28c) rotatably mounted on said auxiliary shaft.
8. Device according to claim 1, characterized in that it comprises a single sliding coupling (26), the primary member of which is fixed to a flange (26c) coupled to said two freewheel mechanisms (30, 32) and mounted to rotate on a drive shaft (24) fastened to said mobile spool (14) and adapted to be coupled to said mobile member of said rotary connection, and in that said arm (22) is also mounted to rotate on said drive shaft.
9. Device according to anyone of claims 1 to 7, characterized in that said arm (22) is generally L-shaped, with one part extending outwardly of said spools and substantially perpendicularly to their axis, its other part being substantially perpendicularly to their said axis , its other part being substantially parallel to said axis and carrying said satellite pulley (20) at its free end.

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